These pages depict Clark Masts
original range of mast products.
These pages depict Clark Masts
original range of mast products.
|A Diversion From Mast Manufacture - The Clark Scamp Moped of 1968|
Scamp Technical Details - The Scamp was a small wheeled bicycle with a gear-case in the rear wheel similar to that of the BSA Winged Wheel. The engine being mounted onto the side of the gear-case with the cylinder angled up towards the front at 45 degrees and placed generally out into the air stream for reasonable cooling. The Scamp's design used quite an unusual means of spinning the engine for starting purposes. The final drive was by a large gear, driven by a pinion, which ran in an oil bath. On the pinion shaft was a centrifugal clutch drum which had a slot machined into it. On the centrifugal clutch, which was mounted directly onto the crankshaft, there was a plastic counterbalanced pawl that was lightly spring loaded to bring it into contact with the clutch drum. As the machine was wheeled forward, the clutch drum rotated and the plastic pawl engaged the slot which in turn caused the engine to turn over. Once the engine was running the centrifugal clutch rotated causing the pawl to overtake the slot and, because it was counterbalanced, it pivoted out of contact with the drum, leaving the engine idling but not driving the rear wheel. As the engine was revved the centrifugal clutch transmitted drive to the rear wheel and, with the help of a couple of pushes on the pedals, the Scamp would get mobile.
Mounted on the left hand side of the rear wheel, the 50 cc piston-ported 2-stroke engine featured radial finning on its alloy head and cast iron cylinder. The crankshaft was unusually constructed in that the flywheels bolted together by socket cap screws through the big-end bearing core with the con-rod seeming to run on uncaged roller bearings, so the whole assembly appeared to be home serviceable with no more than a simple Allen key! A Dansi flywheel magneto set was located on the nearside journal, while the drive was output to a simple single-stage centrifugal clutch.
The rear 'disc' wheel was a primitive assembly comprising of a Dunlop 12"×2" rim bolted and riveted through the spoke holes, to a pressed steel disc form, fixed to a driving flange. It may be of little surprise to find that such wheels often displayed some buckle effects. The flange rotated on bearings around the rear axle, driven on a shaft from a large reduction gear running in an oil-bath alloy case, and powered by a pinion shaft from the clutch drum. Turning a "power key" located in the clutch housing enabled the drive to turn the motor, by a counterbalanced nylon pawl engaged through a slot in the clutch drum. Once the motor was started, centrifugal force overcame a spring to disengage the pawl. The automatic clutch engaged as motor revs were further increased. Turning back the "power key" disabled the pawl as the clutch rotated into contact, returning the Scamp to peddle bicycle mode.
On starting, and once the motor got warm, the Clark Scamp cruised happily up to 25mph, above which, vibrations would start coming in through the Radaelli seat and the ride became uncomfortable. Downhill, 34mph maximum speed was occasionally achievable. Speed fell away readily as the bike encountered any incline, but it usually still managed to labour slowly up moderate hills at low revs without the need to pedal.
Both brakes proved suitably retarding when required, with the rear calliper function proving surprisingly effective, though generally small wheeled machines would typically be expected to deliver better hub braking performance in any case, due to the basic law of physics.
proved to be an unhappy diversion for Alec Clark and his company,
however following discontinuation of the Scamp, the company's portable
air-operated telescopic mast business continued to thrive. Today Teksam NV and Clark Masts Teksam offer over 200 different models
The manufacturer of Clark Masts today, Teksam NV, is represented in Australia and the Asia-Pacific
region by Portable Masts
Australia Pty Ltd.
|Back To - Clark Masts History - Home Page|
Web Articles by the
same author EARLY
YAESU MUSEN EQUIPMENT IN AUSTRALIA
|Links to other pages in this article|
|Page 1||Clark Masts History - Early 1970's QT Mast Series|
|Page 2||Clark Masts History - Early 1970's ST Mast Series|
|Page 3||Clark Masts History - Early 1970's PT Mast Series|
|Page 4||Clark Masts History - Early 1970's WT Mast Series|
|Page 5||Clark Masts History - Early 1970's DAF Mast Series|
|Page 6||Clark Masts History - Early 1970's SCAM Mast Series|
|Page 7||Clark Masts History - Early 1970's PB1 Mast|
|Page 8||Clark Masts History - Early 1970's Surveyor Mast Series|
|Page 9||Clark Masts History - Early 1970's 63/70 Trailer Mounted Mast|
|Page 10||Clark Masts History - Early 1970's 63/100 Trailer Mounted Mast|
|Page 11||Clark Masts History - Early 1970's Mast Fitting and Mountings|
|Page 12||Clark Masts History - Early 1970's Vehicle Mounting Accessories|
|Page 13||Clark Masts History - Early 1970's Air Supply Equipment|
|Page 14||Clark Masts History - Early 1970's Guying Equipment|
|Page 15||Clark Masts History - Early 1970's Antenna Fittings|
|Page 16||Clark Masts History - Early 1970's Miscellaneous Equipment|
|Page 17||Clark Masts History - Early 1970's Antenna Mounting|
|Page 18||Clark Masts History - Early 1970's Useful Wind Information|
|Appendix||Clark Masts History - The 1968 Clark Scamp Moped|
Details On Clark Masts Current Range Of Portable Telescopic Pneumatic Mast Products
page is sponsored by Portable
Masts Australia Pty Ltd
Suppliers of Fast Erecting air operated telescopic portable masts and towers as well as Debeglass Non-Conductive Guy Wire
For product details and a catalogue covering over 200 different mast types of Clark Masts go to PMA's web site.
Phone: +61 402130692
PMA Contact Details
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This page was last updated 05-01-2023
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